Case Studies / uandu GmbH

How uandu GmbH Generated €5,312.53 with a WhatsApp Hack

€5,312

WhatsApp Revenue

€974

WhatsApp Spend

5.45x

ROWAS

Blog Header Image

Written by Johannes Mansbart

CEO & Co-Founder, chatarmin.com

Last updated at: October 02, 2025

Lifestyle

Initial Situation

uandu GmbH, an innovative online retailer for lifestyle and everyday products, wanted to make their Halloween campaign more efficient.
The goal: generate more revenue per campaign – without driving up WhatsApp META costs unnecessarily.

Solution: Retargeting Within the 24h Conversation Window

With Chatarmin, uandu applied a clever WhatsApp hack:

uandu 2-Teilige Halloween Kampagne whatsapp

  • Second message to non-buyers: All contacts who did not convert after the first message received a follow-up just a few hours later.
  • Cost savings: Since both messages were sent within the 24h window, META costs were only charged once.
  • Klaviyo + Shopify integration: Enabled easy creation of a non-buyer segment and automated follow-up messages.

Results

This smart Halloween campaign delivered impressive results:

uandu 2-Teilige Halloween Kampagne KPIs

  • €5,312.53 WhatsApp revenue 💰
  • €974.39 WhatsApp costs
  • 5.45X ROWAS 🚀
  • €51.60 AOV 📦

Conclusion

This case study shows how WhatsApp retargeting within the 24h conversation window is a true performance booster.
By combining precise segmentation, smart cost optimization, and automated setup through Chatarmin, uandu significantly increased the efficiency of their WhatsApp campaign.

👉 Want to learn how your brand can leverage WhatsApp retargeting?
Talk to our team